The present invention relates to a circuit for controlling the transport of containers, freight pallets or the like in mobile cargo space and/or within a system which includes a transport path in and along storage locations for containers, and further includes stationary drives acting on the containers to move them along; the drives are being controlled by a follow-up control logic circuit that is operated from a control panel. The movement, of course, has to be reversible to accommodate loading and unloading.
The transport of containers, pallets or the like for example, in the interior of an airplane, for purposes of loading and unloading, poses certain logistic problems. On one hand the available space is minimal while on the other hand, loading and unloading should take little time only, simply because in terms of flying time loading is an idle period for the aircraft.
Automated control system have been developed and are used for loading and unloading an aircraft, particularly so-called wide body planes. For example, the German printed patent application No. 2,135,925 describes such an automatic transport control system which includes a control panel for operating and controlling the movement to and from storage locations in the cargo space in aircraft under utilization of a programmable follow-up control and logic circuit for purposes of loading and unloading the craft.
Transport and moving of a container is carried out by stationary motor drives, under cooperation with switches, control and latching elements, and so forth. These components are automatically turned on and off as a result of operation of the follow-up control initiated by the operator working the panel. The whole purpose here is that only those elements are turned on, which are immediately affecting the transportation and movement.
Such an automated transport system does not use much energy but requires that no interference occurs. On the other hand, handling of containers in and around aircraft makes almost inevitable that here or there some interfering actions are encountered. They may in some cases be of very minor nature or interference may be caused by ecological or environmental conditions, but as a consequence of even a minor interference, the whole system may come to a halt. As the automation is blocked manually shifting of the containers is required in order to overcome the interference and eliminate further down time. These situations may be inevitable, on one hand, but are still highly undesirable, on the other hand. Correction will be time consuming and, from a logistic point of view, may be quite complicated. The reason for expecting complications is that the various switches associated with the storage locations will in effect be operated by the logic circuit only, but that circuit may not be operative at that point in time.